Gear-cutter.



PATENTED OUT. 29. 1907.

G. D. MARVIN. GEAR GUTTER.

APPLICATION FILED DEG. 3'0. 1905.

Wnmlmll A TTQRNE V5 WITNESSES;

GARRET D. MARVIN, OF'FI'NDLAY, OHI.

GEARLCUTTER';

v Specification-of Letters Patent.

Patented Oct. 29', 1907;

Apnlioation tiled December 30| 1905. Serial No. 2931950.

`J'o all whom it muy concern:

Be it known that I, Gannm D. MARVIN, a citizen of tlfe United States, residing at Findlay, in'th'e county o 'Hancock and State of Ohio, have invented a new and useful Gearlutter, of which the following is a specification.

This'invention relates tov gear cutting machines, and has for its principal objectto provide a device which may be employed as an attachment for lathes in the cutting 'of gears of any type.

A' further object'of the invention is'to provide a gear cutting mechanism of' very simple and inexpensive construction, and which may be handled with ease and connected to and disconnected from a lathe or si milarmechanism bya single operator.

A still further object of the invention is to provide a gear cutting device in Which gears of any size may be cut, and in which a pattern wheelV is employed vfor the purpose of effecting fresh adjustments ofy the blank as tooth after tooth is cut, the pattern wheel being locked after each adjustment, and serving to hold the blank in proper position with respect to the cutter tool.

With these and other objects in View, as will more ully hereinafter appear, the invention consists in certain novel features of construction and arrangement of parts, hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages of the invention.

ln the accompanying drawingsz-Figure 1 is a perspective view of a gear cutting machine constructed in accordance with the invention. Fig. 2 is a vertical section of the same.

Similar numerals of reference are employed to indicate corresponding parts throughout the several figures of the drawings.

The mainframe of the device is in the form of a vertically disposed bar l0 that is provided with a vertical slot ll, extending practically from end to end thereof, and at the base of the bar is a laterally extended foot piece l2 which may be secured to a carrier in any suitable manner, and in Fig. l is shown as secured to the transversely movable carriage A of an ordinary form of lathe, the carriage A being supported as usual on the longitudinally adjustable carriage B, these parts of the mechanism, aswell as the lathe bed C and head stock D being of any ordinary construction.

Arranged in the vertical slot 1l is a rectangular block 15, having an enlarged flange 15 that ts against the outer face of the bar l0. This block is supported by a ring 16, the top of which has a' swiveled connection which rthe screwmaybeturned ifor the purpose of-raisingI and lowering tlieblockf15f That' portionlofth'e" block beyondf the ringf 16" is"circular2 in'form',--and isL threadedffor the reception of 'a nut 19'; which; by-forcing the ring/against the outer-"0r reanface of `the bar 10', prevents any lateral play of2 the 'block-15.

and receives the splithub 20,Y of an'va'rm 21, said-hub being rmlylocked'in place byfalclz'tmpin'gA screwor; bolt 22, so ythat the arm dslheldfronr further revoluble or longitudinal movement.

The block 15 is-providedwithanopenng-forthe passage of r a shaft! 24, .providedf nearV one endi w'itlrifixed flangeor collarr 2-5fthat bears against theouter:`

end of the block, and near its oppo'site'endis threaded:r for-the'reception'ofTanut26, which, in screwing against the fend oftlre block 15,- servesito lroldisaidlshaftfrom any independent longitudinal movement. The inner end of the shaft 24 is stepped, that is to say, is provided With portions of successively smaller diameter that may receive hub bores of different diameter. This permits of the reception of Wheel blanks having bores of different diameter, and the blanks when once adjusted to position are firmly locked in place by a nut 27.

The outer end of the shaft is arranged to receive a pattern wheel 28 having teeth of a number equal t0 the number of teeth to be cut in the blank, although itis not necessary that the pattern Wheel should be of the same diameter as the blank.

The arm 21 hereinbefore referred to, is provided with a vertical slot 29. which receives the vertically adjustable block 30, from which projects a threaded stem 31 carrying a nut 32 by which the block may be locked in any position of adjustment.

The block carries a cylindrical casing 31, through which extends a locking pin 32/ having at its lower end a tooth 33 arranged to engage between the teeth of the pattern wheel, and the tooth is held in position by means of a spring 34 surrounding the pin 32. The upper end of the pin is provided with an enlarged knob or head by which it may be readily raised for the purpose of turning the pattern wheel, this movement being transmitted to the wheel blank at -the opposite end of the shaft.

Near the lower portion of the bar lO'is a vertically adjustable plate 36 Which may be locked in any position of adjustment by bolts 37. This plate carries a screw 38 disposed parallel with the shaft 24 and capable of adjustment in order that it may form a backing for the wheel blank during the cutting operation, the screw serving to engage the rim portion of the wheel at a point adjacent to the line of cut', and holding the l Wheel rim in order to prevent breakage or chattering of the tool.

The cutting tool 4.0 is of any ordinary construction, and, in the present instance, is carried by a spindle 4l having an enlarged head 4-2 which may be secured to the head stock D of the lathe.

In operation, the parts are adjusted in the manner shown in Figs. l, and 2, and the operator then moves the transverse carriage A of the lathe in order to carry the frame l0 in the direction of the cutting tool. This moves the periphery of the blank across the cuttingl tool and makes the iirst cut7 after which the carriage is drawn out and the screw l7 is carried down for the second adjustment, and so on until the cut has reached the desired depth, or the cutting may take place so that successive cuts are formed at successive points, and in this case no adjustmentotthe screw will be necessary until the new blank has inade one complete revolution, and all et the teeth are partly cut.

It will be observed that the adjustment iromtooth to tooth may be quickly accomplished by merely pulling the pin 32 outward and turning the pattern wheel the desired distance.

rlhe frame l0 as a Whole is preferably pivoted, so that it may be adjusted to present the blank at any angle to the horizontal, and thus permit the cutting of a miter or bevel gear.

In order to cut a toothed Wheel having a transversely t l l eoncaved periphery, the blank is not moved transl versely across the lathe, but remains with the center oi the blank in the vertical plane of the axis ot the cutter, so that the periphery of the blank will be coin caved transversely as is usual in Worm gears.

T ie vertical bar l0 is connected to the base piece l2 by a pivot 40, so that the angular position ot the bar may be changed when the teeth ot a bevel gear are to be cut. In order to lock the bar in adjusted position, said bar is provided with an arcuate strip ll/7 having a slot for the reception oi a bolt 42/ that extends into the foot piece l27 there being preferably a locking strip at each side of the bar.

l claim:-

l. The combination o1 a trame, a bearing block adjust. ably mounted thereon. a shaft in the block, a slotted arm adjustably secured lo the block, a pattern wheel on thtx shaft adjacent the arm. a slidably adjustable member on the arm. a device on the member arranged to engage the periphery ot the pattern wheel, and a spring arranger'l to hold the device in engagenient with the wheel.

'lhe combination of a trame, a bearing block adjust ably mounted thereon. a shaft in the block, an arin adjust ably attached to the block, a chambered block adjustable longitudinally ot' the arm, a pin iu the chamber ol' the block and extending at one end ther-col' to t'orm a band hold. and a yieldingl means within the chamber ol the block lor operating on the pin.

ln testimony that I claim the foregoingl as my own. l have hereto atlixed my signature in the presence ol two witnesses.

MARKET l). MARVIN.

Mauroy (t. l `os'r1:u. Ilauviar T. Minuut. 

